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#pike __REAL_VERSION__ 
 
//! Returns the parity of the integer @[value]. If the 
//! parity is odd 1 is returned. If it is even 0 is 
//! returned. 
int(0..1) parity(int(0..) value) { 
  if(value<0) error("Parity can not determined for negative values.\n"); 
  return Gmp.mpz(value)->popcount()&1; 
} 
 
constant NATIVE_MIN = __builtin.NATIVE_INT_MIN; 
constant NATIVE_MAX = __builtin.NATIVE_INT_MAX; 
 
//! @decl constant NATIVE_MIN; 
//! @decl constant NATIVE_MAX; 
//! 
//! The limits for using the native representation of integers on the 
//! current architecture. Any integer that is outside this range uses 
//! a more complex and slower representation. Also, some builtin 
//! functions that don't expect very large integers might start to 
//! complain about invalid argument type when given values outside 
//! this range (they typically say something like "Expected integer, 
//! got object"). 
//! 
//! @[NATIVE_MIN] is not greater than @expr{-2147483648@} 
//! (@expr{-0x80000000@}). 
//! 
//! @[NATIVE_MAX] is not less than @expr{2147483647@} 
//! (@expr{0x7fffffff@}). 
//! 
//! @note 
//! The size of the native integers can be controlled when Pike is 
//! compiled with the configure flags @expr{--with-int-int@}, 
//! @expr{--with-long-int@}, and @expr{--with-long-long-int@}. The 
//! default is to use the longest available integer type that fits 
//! inside a pointer, which typically means that it's 64 bit on "true" 
//! 64 bit architectures. 
//! 
 
//! Swaps the upper and lower byte in a word. 
//! 
//! @seealso 
//!   @[swap_long()] 
int(0..65535) swap_word(int(0..65535) i) { 
  return ((i&255)<<8) | ((i&(255<<8))>>8); 
} 
 
//! Swaps the upper and lower word in a longword, and the upper and 
//! lower bytes in the words. Simply put, the bytes are reversed. 
//! 
//! @seealso 
//!   @[swap_word()] 
int(0..4294967295) swap_long(int(0..4294967295) i) { 
  return ((i&255)<<24) | ((i&(255<<8))<<8) | 
    ((i&(255<<16))>>8) | ((i&(255<<24))>>24); 
} 
 
//! Reverses the order of the low order @[bits] number of bits 
//! of the value @[value]. 
//! 
//! @note 
//!   Any higher order bits of the value will be cleared. 
//!   The returned value will thus be unsigned. 
//! 
//! @seealso 
//!   @[reverse()], @[swap_word()], @[swap_long()] 
int(0..) reflect(int value, int(0..) bits) 
{ 
  int aligned_bits = bits; 
  if (bits & (bits-1)) { 
    // Find the closest larger even power of two. 
    aligned_bits <<= 1; 
    while (aligned_bits & (aligned_bits-1)) { 
      aligned_bits -= (aligned_bits & ~(aligned_bits-1)); 
    } 
  } 
  bits = aligned_bits - bits; 
  // Perform pair-wise swapping of bit-sequences. 
  int mask = (1<<aligned_bits)-1; 
  int filter = mask; 
  while (aligned_bits >>= 1) { 
    filter ^= filter>>aligned_bits; 
    value = (value & filter)>>aligned_bits | 
      (value & (filter^mask))<<aligned_bits; 
  } 
 
  // Adjust the returned value in case we've swapped more bits 
  // than needed. We then have junk in the lowest order bits. 
  return value>>bits; 
} 
 
//! The type of @[Int.inf]. Do not create more instances of this. 
class Inf { 
 
  protected constant neg = 0; 
  protected int __hash() { return 17; } 
  protected int(0..1) _equal(mixed arg) { 
    if(neg && arg==-Math.inf) return 1; 
    if(!neg && arg==Math.inf) return 1; 
    return arg==this; 
  } 
  protected int(0..1) _is_type(mixed type) { return (< "int", "object" >)[type]; } 
  protected mixed _random(function rnd_string, function rnd) { 
    if (neg) return 0; 
    return this; 
  } 
  protected mixed _sqrt() { return this; } 
  // % == nan 
  // & == nan 
  protected mixed `*(mixed arg) { 
    int n = neg; 
    if(arg<0) n = !n; 
    if(n) return ninf; 
    return inf; 
  } 
  protected mixed ``*(mixed arg) { return `*(arg); } 
  protected mixed `+(mixed arg) { 
    if(arg==`-()) error("NaN\n"); 
    return this; 
  } 
  protected mixed ``+(mixed arg) { return ``+(arg); } 
  protected mixed `-(void|mixed arg) { 
    if(!query_num_arg()) { 
      if(neg) return inf; 
      return ninf; 
    } 
    if(arg==inf || arg==ninf) error("NaN\n"); 
    return this; 
  } 
  protected mixed ``-(mixed arg) { 
    if(arg==inf || arg==ninf) error("NaN\n"); 
    return this; 
  } 
  protected int(0..1) `<(mixed arg) { 
    if(arg==this) return 0; 
    return neg; 
  } 
  protected int(0..1) `>(mixed arg) { 
    if(arg==this) return 0; 
    return !neg; 
  } 
  protected mixed `~() { return `-(); } 
  protected mixed `<<(mixed arg) { 
    if(arg<0) error("Got negative shift count.\n"); 
    return this; 
  } 
  protected mixed ``<<(mixed arg) { 
    if(arg<0) return ninf; 
    return inf; 
  } 
  protected mixed `>>(mixed arg) { 
    if(arg<0) error("Got negative shift count.\n"); 
    return this; 
  } 
  protected mixed ``>>(mixed arg) { 
    return 0; 
  } 
  protected mixed cast(string to) { 
    switch(to) { 
    case "string": 
      return "inf"; 
    case "float": 
      return Math.inf; 
    default: 
      return UNDEFINED; 
    } 
  } 
  protected string _sprintf(int t) { 
    return t=='O' && (neg?"-":"")+"Int.inf"; 
  } 
} 
 
class NInf { 
  inherit Inf; 
  constant neg = 1; 
} 
 
protected Inf ninf = NInf(); 
 
//! An object that behaves like positive infinity. 
Inf inf = Inf();